<!DOCTYPE html>
<html lang="zh-CN">

<head>
    <meta charset="UTF-8">
    <title>04_字体粗细</title>
    <style>
        .atguigu1 {
            font-size: 100px; 
            font-weight: lighter;
        }
        .atguigu2 {
            font-size: 100px;
            font-weight: normal; 
        }  
        .atguigu3 {
            font-size: 100px;
            font-weight: bold; 
        }  
        em {
            font-size: 100px;
            font-weight: 900;
        }
    </style>

</head>

<body>
    <div class="atguigu1">尚硅谷1</div>
    <div class="atguigu2">尚硅谷2</div>
    <div class="atguigu3">尚硅谷3</div>
    <em>尚硅谷2</em>
</body>

</html>